TECHNICAL PROBLEMS POSED BY THE PRIOR ART
Closures of various types have been proposed in the prior art for use with containers to resist removal of the closure. Some types provide a visual indication that the container has been subjected to a previous opening attempt. This alerts a consumer to the possibility of a previous attempt to tamper with the container or contents. Various arrangements of such closure structures are sometimes referred to as pilfer bands, tamper bands, guarantee bands, security rings, tamper-indicating closures, tamper-evident closures, etc.
In many applications, at least the closure is fabricated from a synthetic, plastic material, and the container is also typically fabricated from a synthetic plastic material. With some prior art tamper-evident closures, a tamper-evident band of the same material must be torn from the closure or container. This results in a piece of waste material which must be discarded and which is frequently dropped as litter. It would be desirable to provide an improved closure in which a tamper-evident band remains mounted on the container so that it does not contribute to a littering problem and so that it clearly indicates that the container has been opened.
Some tamper-evident closures include engaging structures which are visible and, to some extent, accessible when the container is closed. Such structures may be susceptible to manipulation and/or deforming operations which may permit removal and replacement of the closure without providing the intended visual indication. It would be preferable to provide an improved tamper-evident closure which could not be so easily defeated.
It would also be advantageous to provide such an improved closure with a structure that would accommodate assembly onto the container by automatic closure-applying apparatus as well as manually.
In addition, it would be beneficial if a removal-resistant structure could be incorporated in a closure (or other member) mounted on a container in a way that would not create excessively large stresses or cause an increase in the diameter of the closure. Further, it would be advantageous if such an improved structure projected radially inwardly and outwardly only a relatively small amount so as to provide a relatively thin circumferential structure around the container.
In addition, it would be desirable if such an improved removal-resistant structure could be provided with a configuration for accommodating assembly onto the container without requiring excessive application forces. However, it would also be beneficial if such an improved structure could be configured to provide increasing engagement forces and increasing resistance to removal in response to increasing removal forces.
An improved removal-resistant closure or member should preferably also have a structure that would accommodate high speed, low-cost manufacture, such as by molding from plastic material. To this end, a salutary feature of an improved structure would be a configuration that could be molded without the use of a side action mold. Preferably, such an improved structure should also have the capability for being molded and released from the mold without being subjected to high distortion forces that are sometimes associated with some conventional mold product release operations.
Also, it would be desirable to provide a removal-resistant member that could be relatively easily mounted on a container for attaching to the container a variety of objects (e.g., a closure integral with the member, an auxiliary closure, a tag, or other device which is intended to be used with, on, or about the container).
Finally, it would be desirable to provide an improved removal-resistant structure and method for fabricating the structure wherein the structure can be molded from plastic material and does not require secondary operations (such as subsequent forming, heating, or shaping) in order to complete the fabrication.